Hes@ks369516:~$ sudo do-release-upgrade -d
Checking for a new ubuntu release
Get:1 Upgrade tool signature [198B]
Get:2 Upgrade tool [1307kB]
Fetched 1307kB in 0s (0B/s)
extracting 'natty.tar.gz'
authenticate 'natty.tar.gz' against 'natty.tar.gz.gpg'
Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Building data structures... Done
Invalid package information
After your package information was updated the essential package
'ubuntu-minimal' can not be found anymore.
This indicates a serious error, please report this bug against the
'update-manager' package and include the files in
/var/log/dist-upgrade/ in the bug report.
Restoring original system state
Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done
Building data structures... Done
=== Command detached from window (Tue May 24 08:44:56 2011) ===
=== Command terminated with exit status 1 (Tue May 24 08:44:56 2011) ===